How well will survey data tell us how the delegates will be divided in the Texas caucuses? Well, if the earlier caucus states are any guide, the polls won't do very well. Since (and including) Super Tuesday, there have been four states where we had polling data in advance of caucuses held in those states (most states with caucuses were not surveyed by the pollsters). The table below shows the delegate counts that I estimated prior to those caucuses using the survey data. The table also shows the actual delegate totals that the candidates received in those caucuses.
Note that only in New Mexico were the polling-based estimates a reasonable guide for predicting how the delegate totals would actually turn out. This is not surprising since the "caucuses" in New Mexico were more like a party-run primary (voters simply cast ballots). In the other states, where more traditional caucuses were held, the estimates were off significantly. (Texas's caucuses are of the more traditional Iowa-style variety).
Overall, the polling suggested that Obama and Clinton would divide the delegates in these caucuses relatively evenly, but Obama won 65% of the delegates available in these states while Clinton won just 35%. Right now, the polling in Texas shows a roughly even contest. However, if we extrapolate from what has happened in other caucus states, then we can estimate that Obama will take about two-thirds of the delegates up for grabs in the Texas caucuses. Thus, even if the candidates break even in the primary, Obama could win between 40-45 delegates in the caucuses compared to just 23-27 for Clinton. This would potentially give Obama a net gain of about 20 delegates out of Texas, which would likely off-set any gains Clinton would receive from Ohio and Rhode Island. Of course, this is assuming that Obama shows a similar strength in Texas's caucuses as he has in other states. It will be interesting to see if this pattern holds up.